Investigating Materials

Scientists at the German Engineering Materials Science Centre (GEMS) of the HZG examine structures 10,000 times thinner than a strand of hair using instruments the size of a city block. They want to uncover how hydrogen is distributed in a tank during loading or how materials behave during a welding process.

There are numerous questions that can only be answered by utilising special “supermicroscopes” and “supercameras.”

Apart from collaborating with the material scientists at the HZG, the GEMS researchers also support scientists from the most varying range of disciplines from all over the world. In doing so, even the inside of a fossilised dino egg can sometimes be made visible.

Solving Materials Problems with Supermicroscopes

The widest array of materials can be analysed and characterised in a non-destructive manner at the German Engineering Materials Science Centre (GEMS). In order to do so, the scientists make their instruments available at the PETRA III synchrotron ring in Hamburg and at the FRM II reactor in Garching near Munich. The experts in the field of photons and neutrons serve in an advisory capacity and offer support not only with the experiments themselves, but also with data analysis.

Why Use X-ray Technology?

Synchrotron radiation occurs when charged particles in an accelerator ring (PETRA III at the DESY in Hamburg) spiral: electrons, moving nearly at the speed of light, lose part of their energy by emitting a high intensity light beam when they are guided by magnets around a curve.This light beam is an ideal tool for scientists.

The reason: in the X-ray range, the light from an accelerator is up to one million times brighter than an X-ray tube used in a medical office. Moreover, synchrotron radiation is almost as concentrated (“collimated”) as a laser beam. Because the wavelength of this radiation is clearly smaller than that of visible light, nanometre-sized structures and even atoms in some cases can be detected. Researchers from nearly all disciplines make use of synchrotron light to examine their specimens and samples, which include metals as well as plastics and protein molecules.

Why Use Neutrons for Research?

Instrument SANS1 at the FRM II in Garching. [Foto: W. Schürmann, TUM]

Scientists rely on neutrons when they can no longer proceed with photons: X-rays are limited when penetrating many metals. Neutrons, however, can screen an entire engine block. Neutrons are tiny portions of atomic nuclei.

Because neutrons are electrically neutral, they can penetrate deeply into a material. From their measurement data, experts can determine a specimen’s structure in detail. Material properties can be optimised and new materials can be tailored based on this knowledge.

The Platform

A Detailed Glimpse

Helmholtz Program

Within the Helmholtz research field "Structure of Mattert" the Helmholtz-Zentrum Geesthacht participates the research programme "Research with photons, neutrons and ions".

Steckbrief Institut

Structural Research on New Materials: Structural research on hard materials. This primarily includes the characterisation of materials and magnetic substances with the aid of neutrons and synchrotron radiation.

Within the Helmholtz research field "Structure of Mattert" the Helmholtz-Zentrum Geesthacht participates the research programme "Research with photons, neutrons and ions".

Improving Motors with HEMS

The High Energy Materials Science Beamline (HEMS) uses particularly intense X-ray energy to penetrate very deeply into materials. Researchers can see through an entire automotive engine using the HEMS instrument. They search for internal stresses introduced into the component during the production process.

Tears could develop at these locations. HEMS offers tomography capability: here the researchers turn the component in the beam and create numerous layered images, which they assemble into one 3-D version of the specimen – similar to how computer tomography in a hospital provides images of the patient's inner body.

A Live Experiment: Joining with X-Rays

Steckbrief Institut

Structural Research on New Materials: Structural research on hard materials. This primarily includes the characterisation of materials and magnetic substances with the aid of neutrons and synchrotron radiation.

Dino Eggs in the Synchrotron

Photo: Gabryelalaval/Fotolia

150 million years. That’s the age of the fossilised eggs that were placed into the photon beam. The extremely valuable dino fragments must be examined using destruction-free methods. This is why Portuguese dino researchers turned to the GEMS.

The international research team was thus able to close a gap in dinosaur evolution: thanks to the study utilising photon light, they uncovered which eggshell characteristics were inherited from ancestors and which ones were acquired during the course of evolution.

150-million-year-old eggs look different than more recent 80-million-years-old eggs. The highly detailed images show, for the first time, that the surfaces of the eggs exhibit more ribs than the younger eggs. The older eggs also possess only a single outer shell layer, thus resembling crocodile eggs.

The 80-million-year-old eggs, however, have two to three outer layers, precisely the numbers exhibited in today’s bird eggs. The results even permit the researchers to come to conclusions about breeding behaviour, a behaviour that still occurs today in sea-turtle populations. Sea-turtles bury their eggs in sand pits to protect them from predators.

Steckbrief Institut

Structural Research on New Materials: Structural research on hard materials. This primarily includes the characterisation of materials and magnetic substances with the aid of neutrons and synchrotron radiation.